Apparatus for adjusting fuel delivery in diesel injectors

ABSTRACT

A process and apparatus for accurately and inexpensively adjusting fuel delivery through an orifice plug of a Diesel fuel injector. The process includes a first step of enlarging an orifice in the orifice plug and a second step of closing down an end of such orifice if necessary to accomplish the desired flow. The apparatus comprises a holder in combination with an orifice enlarging member and a peening member for closing down the orifice if necessary to the desired flow.

States Uite Errett Nov. 12, 1974 1 1 APPARATUS FOR ADJUSTING FUEL DELIVERY 1N DIESEL INJECTORS [76] Inventor: Carl G. Errett, 1068 River Rd.,

Sweet Home, Oreg. 97386 [22] Filed: July 23, 1973 [21] App]. No.: 381,867

[52] US. Cl. 72/477, 29/157 C [51] Int. Cl B21d 41/00 [58] Field of Search 72/367, 377,477,483; 29/157 C, 406; 239/546; 30/360, 361; 76/107 A, 107 S [56] References Cited UNITED STATES PATENTS 1,635,945 7/1927 Lewis et a1 76/107 1,789,719 1/1931 Weutherhead 29/157 1.975.029 9/1934 Walker 29/157 3.150.442 9/1964 Straw c1111... 29/157 3.641.802 2/1972 Segro 72/377 Primary Examiner-Lowell A. Larson Attorney, Agent, or Firm-Eugene M. Eckelmun [57] ABSTRACT A process and apparatus for accurately and inexpensively adjusting fuel delivery through an orifice plug of a Diesel fuel injector. The process includes a first step of enlarging an orifice in the orifice plug and a second step of closing down an end of such orifice if necessary to accomplish the desired flow. The apparatus comprises a holder in combination with an orifice enlarging member and a peening member for closing down the orifice if necessary to the desired flow.

6 Claims, 4 Drawing Figures APPARATUS FOR ADJUSTING FUEL DELIVERY IN DIESEL INJECTORS BACKGROUND OF THE INVENTION This invention relates to a new and novel process for adjusting fuel delivery to Diesel injectors and to apparatus for accomplishing the same.

A common type of Diesel fuel injector employs an orifice plug through which Diesel fuel is delivered to the injector. These orifice plugs can be replaced if necessary but such is an expensive process and in addition the precise fuel flow desired cannot be achieved. It is the practice to use a burnishing tool to enlarge the ori fice but one disadvantage in using such a tool is that the latter requires a substantial amount of experience because of its manner of use and its micrometer settings. Often, the-workman makes the orifice too large which of course ruins the orifice plug and a new one must be substituted. This has been found to be expensive and time consuming. In addition to the cost being great because of wasted plugs and time, the burnishing tool itself which is now in use is very expensive.

SUMMARY OF THE INVENTION According to the present invention and forming a primary objective thereof, a process and apparatus of adjusting fuel delivery to a Diesel injector is provided which facilitate rapid and inexpensive adjustment and also which require a minimum of experience.

A more particular object of the present invention comprises a process of adjusting fuel delivery to Diesel injectors wherein the fuel inlet orifice is enlarged to the desired diameter and then reduced if necessary to provide the precise opening for the desired fuel delivery.

Likewise, it is an object of the invention to provide apparatus utilizing a simplified burnishing tool for enlarging the orifice as desired and also utilizing a peening tool for reducing the size of the orifice slightly if necessary to accomplish the desired fuel delivery.

The invention will be better understood and additional objects and advantages will become apparent from the following description taken in connection with the accompanying drawings which illustrate a preferred form of the device.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is an elevational view, partly broken away, of a Diesel fuel injector and also showing a portion of the present device mounted thereon;

FIG. 2 is an enlarged fragmentary tip end view of a burnishing tool forming a part of the invention;

FIG. 3 is an elevational view of a peening tool which also forms a part of the invention; and

FIG. 4 is an enlarged fragmentary sectional view of an orifice plug showing a peening operation by the peening tool.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT Referring in particular to FIG. 1, the numeral designates generally an injector assembly. Such an assembly comprises a holder 12 having attaching means such as a locating setscrew 14 for securement of the holder to an injector 16 having briefly an adapter portion 18, a lower cup retainer 20 for a cup portion 22, and a tip 24 on the cup portion. The inlet of fuel to the injector is through an orifice plug 26 threadedly mounted in a tapped bore 28 leading laterally into a side of the injector. Plug 26 has a central orifice 30 which by its diameter meters the flow of fuel into the injector. A passageway 32 is provided in the injector having communication with the orifice 30 and it is through this passageway that fuel is admitted to the injector and injected out the tip by a plunger, not shown. Such plunger is operated by a link 34 driven downwardly by conventional cam means and driven upward by plunger return spring 36.

The holder 12 has a tapped bore 40 which in the mounting position of the holder for the injector is precisely axially aligned with the tapped bore 28 in the injector body. When in use position on the engine, the holder has threaded connection with fuel supply means such as a conduit. Such conduit is not shown but instead apparatus of the present invention, to be described, is shown in temporary installed position. Suitable O-rings 42 are mounted on the external surface of the adapter 18 to provide a fluid tight surface connection between the injector and the holder.

The invention resides in a process of enlarging the orifice 30 and of adjusting such orifice down if necessary into a precise fuel metering size. Apparatus for carrying out such method is as follows:

A first portion comprises a guide member 44. This guide member has a body portion 46 terminating at one end in a threaded shank 48 arranged to be threadedly engaged in tapped bore 40 of the holder 12. Body portion 46 has a head 50 at the end opposite from the threaded shank 48 which may form an integral part of the body portion or as shown it may be mounted on a threaded end portion 52 thereof. The enlarged head 50 has a knurled gripping surface 54.

Body portion 46 has a smooth axial bore 55 therethrough arranged slidably to receive a rod-like burnishing member 56 supporting a pointed tip 58 at its forward end, also seen in FIG. 2. Tip 58 is removably attached to the member 56, as by means of a setscrew 60,

with the result that different diameter tips may be substituted one for the other. The opposite end of member 56 has a striking head 62 provided with a knurled gripping surface 64.

Also forming a part of the present invention is a rodlike peening member 68, FIG. 3, terminating at its rearward end in a flat striking end and at the forward end in a narrowed flat peening end 72. Thediameter of the peening end 72 is less than the diameter of recess 31 so that this end of the member 68 can be inserted in such recess for its function, to be described. The diameter of such peening end 72 is, however, larger than the diameter of the orifice 30, this end of the tool being ground so as to have a taper 73 providing the desired end diameter. This peening member is of the same diameter as the member 56 in its body portion and is adapted to have slidable guided movement through the bore 55 of guide member 44.

In the adjustment of an injector for the purpose of injecting a precise amount of fuel, the injector and its holder are taken off the engine and mounted on a calibrating machine of a type capable of determining proper flow from the tip end of the injector, the inlet conduit to the injector being unthreaded from the aperture 40 when the injector is removed from the engine. The test operator then installs a suitable orifice plug 26 or enlarges orifice 30 if necessary to achieve the de sired fuel flow into the nozzle. For enlarging the orifice 30 by the instant invention, the guide member 44 is installed in the tapped bore 40 and the burnishing member 56 inserted in the axial bore of such guide member, the test operator first installing a proper size tip 58 which will enlarge the orifice 30 as desired. Such enlarging of the orifice is accomplished by moving the burnishing member inwardly until the tip engages orifice 30 and then lightly tapping the head 62 of rod member 56 by a hammer. In the event that the orifice 36 is made too large by the tip 58,it is merely necessary for the operator to remove the burnishing member 56 and insert the peening member 68. By lightly pounding the end 70 of the peening member 68 with a hammer, the necessary peening of metal at the outlet end of the orifice 30 is accomplished. As seen in FIG. 4, such peening causes outer end defining portions of the end of the orifice to peen inwardly, as represented by the numeral 74, to reduce the effective diameter of such orifice as desired.

By means of the present tool a test operator with a minimum of experience can precisely adjust the fuel delivery of an injector. Such may be accomplished when necessary by enlarging the orifice 30 in the orifice plug and if the orifice should accidentally be made too large it is merely necessary to peen the end defining wall of the orifice over with the member 68 rather than throwing the plug 26 away and inserting a new one. Thus, the adjusting of fuel delivery in an injector by the present invention is made greatly simplified and can be done by almost any mechanic. Also, the invention has the advantage that the tool cost is extremely low and the time involved in making suitable adjustment is considerably less. Most of all, however, with the present invention, precise fuel flow can be obtained.

It is to be understood that the form of my invention herein shown and described is to be taken as a preferred example of the same and that various changes in the shape, size and arrangement of parts may be resorted to without departing from the spirit of my invention, or the scope of the subjoined claims.

Having thus described my invention, 1 claim:

1. Apparatus for adjusting fuel delivery to a Diesel injector having an orifice plug and a fuel delivery orifice therethrough comprising a holder, means defining a bore through said holder, means on said holder arranged to secure it to the injector with the bore thereof in alignment with the orifice in the orifice plug, orifice enlarging means insertable into said bore arranged to engage said orifice and enlarge the latter, and peening means insertable into said bore arranged to peen one end of the orifice for reducing fuel delivery therethrough.

2. The apparatus of claim 1 wherein said orifice enlarging means comprises a rod-like member having slidable guided movement in said bore and being of greater length than said holder, and a tip on one end of said rod-like member of reduced diameter engageable with the orifice.

3. The apparatus of claim 2 wherein said tip is removable from said rod-like member for interchangeability of different diameter tips.

4. The apparatus of claim 1 wherein said orifice enlarging means comprises a rod-like member having slidable guided movement in said bore and being of greater length than said holder, a tip on one end of said rod-like member of reduced diameter engageable with the orifice, and a striking end on said rod-like member on the end opposite from said tip end.

5. The apparatus of claim 1 wherein said peening means comprises a rod-like member having a substantially flat peening end of a diameter slightly greater than the diameter of said orifice, said peening means being of greater length than said holder.

6. The apparatus of claim 1 wherein said peening means comprises a rod-like member having a substantially flat peening end of a diameter slightly greater than the diameter of said orifice, said peening means being of greater length than said holder, and a striking end on said rod-like member on the end opposite from said peening end. 

1. Apparatus for adjusting fuel delivery to a Diesel injector having an orifice plug and a fuel delivery orifice therethrough comprising a holder, means defining a bore through said holder, means on said holder arranged to secure it to the injector with the bore thereof in alignment with the orifice in the orifice plug, orifice enlarging means insertable into said bore arranged to engage said orifice and enlarge the latter, and peening means insertable into said bore arranged to peen one end of the orifice for reducing fuel delivery therethrough.
 2. The apparatus of claim 1 wherein said orifice enlarging means comprises a rod-like member having slidable guided movement in said bore and being of greater length than said holder, and a tip on one end of said rod-like member of reduced diameter engageable with the orifice.
 3. The apparatus of claim 2 wherein said tip is removable from said rod-like member for interchangeability of different diameter tips.
 4. The apparatus of claim 1 wherein said orifice enlarging means comprises a rod-like member having slidable guided movement in said bore and being of greater length than said holder, a tip on one end of said rod-like member of reduced diameter engageable with the orifice, and a striking end on said rod-like member on the end opposite from said tip end.
 5. The apparatus of claim 1 wherein said peening means comprises a rod-like member having a substantially flat peening end of a diameter slightly greater than the diameter of said orifice, said peening means being of greater length than said holder.
 6. The apparatus of claim 1 wherein said peening means comprises a rod-like member having a substantially flat peening end of a diameter slightly greater than the diameter of said orifice, said peening means being of greater length than said holder, and a striking end on said rod-like member on the end opposite from said peening end. 